A manualized treatment approach will be developed for people with comorbid panic disorder (PD) and asthma. PD is much more common among asthmatics than in the general population, and there is evidence that asthma and PD may mutually exacerbate each other. This occurs through mechanisms that are physiological (autonomic hyperreactivity, hyperventilation, effects of medications), cognitive (fear of respiratory-linked body sensations, faulty discrimination between asthma and panic symptoms), and behavioral (inappropriate behavioral and pharmacological interventions). This project will integrate well-validated manualized treatment approaches for panic ("panic control therapy") and asthma ("asthma education"), and add components of particular importance to the comorbid group (e.g., discriminating between panic and asthma symptoms and between adaptive asthma-specific panic and maladaptive generalized panic, reconciling superficially contradictory recommendations given in asthma and panic therapies). During the first year a manual will be expanded and tested on 10 comorbid subjects. During the next two years, it will be refined and pilot tested on 40 comorbid subjects, using a waiting list control and a 6-month follow-up. The principal outcome measures will be indices of high/low PD end-state functioning and improvement in asthma severity. A number of exploratory measures also will be analyzed.